Method of laser micro-machining stainless steel with high cosmetic quality

Abstract

A process to laser micro-machine a metal part with a high cosmetic quality surface includes applying a protective coating layer to at least one surface of the part before micro-machining the part with a laser. The protective coating applied to the high quality cosmetic surface can have a thickness of between about 5 mil and about 10 mil, inclusive and have sufficient adhesion strength to adhere to the part without delaminating during processing. The protective coating applied to the machining surface of the part can be a metallic material, such as a metallic foil or tape.

1 . In a process to laser micro-machine a metal part with a high cosmetic finish quality surface and an opposing surface, the improvement comprising:
 applying a protective coating layer to at least one of the high cosmetic finish quality surface and the opposing surface before micro-machining the part with a laser.   
   
   
       2 . The process of  claim 1  wherein the protective coating layer is applied to a one of the high cosmetic finish quality surface and the opposing surface to be machined, the protective coating layer being sufficiently thin such that a processing time for machining the metal part with the protective coating layer is about equal to a processing time for machining the metal part without the protective coating layer, the protective coating layer being at least one of sufficiently thick to prevent debris splash from burning through the protective coating layer to embed on the opposing machining surface and made of a material with a high enough melting point to prevent the debris splash from burning through the protective coating layer to embed on the opposing machining surface 
   
   
       3 . The process of  claim 2  wherein the material of the protective coating layer is a metallic material. 
   
   
       4 . The process of  claim 1  wherein the protective coating layer is at least one of a copper foil, an aluminum foil and a sheet of stainless steel. 
   
   
       5 . The process of  claim 1  wherein the metal part comprises a stainless steel. 
   
   
       6 . The process of  claim 1  wherein the protective coating layer is applied to the high cosmetic finish quality surface and comprises one of an organic material and an inorganic material serving as a sacrificing layer to block/consume oxygen in air from the high cosmetic finish quality surface during laser irradiation. 
   
   
       7 . The process of  claim 6  wherein the organic material is an adhesive polymer. 
   
   
       8 . The process of  claim 6  wherein the the laser is a nano-second pulse width laser. 
   
   
       9 . The process of  claim 1  wherein the protective coating layer is a first protective coating layer applied to the high cosmetic finish quality surface and comprises a metallic material. 
   
   
       10 . The process of  claim 9  wherein the laser is a micro-second pulse width laser. 
   
   
       11 . The process of  claim 9  wherein the metal part comprises a stainless steel and the first protective coating layer comprises at least one of a copper foil, an aluminum foil and a sheet of stainless steel. 
   
   
       12 . The process of  claim 9 , further comprising:
 applying a second protective coating layer to the opposing surface.   
   
   
       13 . The process of  claim 12  wherein the second protective coating layer comprises at least one of a clear adhesive tape and a transparent blue adhesive tape. 
   
   
       14 . The process of  claim 1  wherein the laser comprises at least one of a nano-second pulse width laser and a micro-second pulse width laser. 
   
   
       15 . The process of  claim 1  wherein the protective coating layer is a first protective coating layer applied to the opposing surface and a second protective coating applied to the high cosmetic finish quality surface, at least one of the first protective coating layer and the second protective coating layer comprising a metallic material. 
   
   
       16 . In a process to laser micro-machine a stainless steel part with a high cosmetic quality surface and an opposing surface, the improvement comprising:
 applying a first protective coating layer to a one of the high cosmetic quality surface and the opposing surface intended to be machined before micro-machining the part with a laser, the protective layer comprising a metallic material including at least one of aluminum, copper and stainless steel; and   micro-machining the one of the high cosmetic quality surface and the opposing machining surface with the laser, the laser including one of a nano-second pulse width laser and a micro-second pulse width laser.   
   
   
       17 . The process of  claim 16 , further comprising:
 applying a second protective coating layer to the other of the high cosmetic quality surface and the opposing surface before micro-machining the part with the laser.   
   
   
       18 . The process of  claim 17  wherein the second protective coating layer comprises one of the metallic material and an adhesive polymer.